The chemical composition obtained by hydrodistillation from twelve species of Myrtaceae (Calycolpus goetheanus, Eugenia biflora, E. flavescens, E. patrisii, E. protenta, E. punicifolia, Myrcia bracteata, M. cuprea, M. fallax, M. multiflora, M. rufipila and Myrciaria tenella) growing wild in the coastal area of the north of Brazil (sandbank of the beach of Marieta, municipality of Maracana, State of Para) was analyzed by GC-FID and GC-MS. Despite the high content of 1,8-cineole in C. goetheanus and alpha- and beta-pinene in E. biflora, all oils were sesquiterpenoid in nature, characterized by high amount of cyclic sesquiterpenes, mostly beta-caryophyllene, germacrene D, bicyclogermacrene, trans-muurola-3,5-diene, trans-cadina-1,4-diene, beta-elemene, alpha-bisabolol, beta-selinene, alpha-selinene, delta-cadinene and gamma-elemene.